This study aimed to estimate the Greek population's maternal dietary intake, physical activity status, and body composition during pregnancy. Forty-nine women during pregnancy, with a mean age of 31.08 ± 4.90 years old, were asked to fill in the Pregnancy Physical Activity Questionnaire (PPAQ) to assess their physical activity levels, the Food Frequency Questionnaire (FFQ) to assess the maternal dietary intake, and a Bioelectrical Impedance Analysis (BIA) to evaluate different body composition indices. Variance analysis showed that the pregnancy trimester's effect on various indices of BIA was statistically significant. Moreover, the results showed that pregnant women consume a median of 2135 kcal and 2012.10 mL of water per day, regardless of their trimester. The Pearson correlation analysis unveiled a significant positive correlation between energy (r = 0.795, < 0.001), water (r = 0.759, < 0.001), fat (r = 0.535, = 0.029), and dietary fibers (r = 0.310, < 0.001) with pregnancy trimester. According to the PPAQ in women, categorized based on their pregnancy trimester, the results showed that women in the third trimester were statistically more sedentary than those in the second and first trimesters, respectively. Lastly, multiple regression analysis showed that pregnancy trimester ( = 0.005), employment status ( = 0.040), economic status ( = 0.037), and higher BMI ( = 0.013), BFMI ( = 0.017), and FFMI ( = 0.024) values had a significant contribution to the model. Pregnancy trimester has a significant impact on different indices of BIA and nutrients based on the FFQ, while physical activity levels decrease dramatically during pregnancy.
